From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id E49071A2BFB for ; Tue, 15 Sep 2015 02:29:54 +1000 (AEST) Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 1D4091400CB for ; Tue, 15 Sep 2015 02:29:53 +1000 (AEST) Received: from /spool/local by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 14 Sep 2015 10:26:21 -0600 Received: from b03cxnp08025.gho.boulder.ibm.com (b03cxnp08025.gho.boulder.ibm.com [9.17.130.17]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 523E83E40076 for ; Mon, 14 Sep 2015 10:25:25 -0600 (MDT) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t8EGO9LL3604796 for ; Mon, 14 Sep 2015 09:24:17 -0700 Received: from d03av01.boulder.ibm.com (localhost [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t8EGOpUN026209 for ; Mon, 14 Sep 2015 10:24:52 -0600 Date: Mon, 14 Sep 2015 09:24:26 -0700 From: Nishanth Aravamudan To: "Aneesh Kumar K.V" Cc: Anshuman Khandual , linuxppc-dev@ozlabs.org, mikey@neuling.org Subject: Re: [RFC] powerpc/hugetlb: Add warning message when gpage allocation request fails Message-ID: <20150914162426.GA54362@linux.vnet.ibm.com> References: <1442212051-15235-1-git-send-email-khandual@linux.vnet.ibm.com> <87egi1f7t6.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <87egi1f7t6.fsf@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 14.09.2015 [18:59:25 +0530], Aneesh Kumar K.V wrote: > Anshuman Khandual writes: > > > When a 16GB huge page is requested on POWER platform through kernel command > > line interface, it silently fails because of the lack of any gigantic pages > > on the system which the platform should have communicated through 16GB memory > > blocks in the device tree during boot time. For example > > > > [ 0.480940] HugeTLB registered 16 GB page size, pre-allocated 0 pages > > [ 0.480945] HugeTLB registered 16 MB page size, pre-allocated 16 pages > > > > This adds a warning message during alloc_bootmem_huge_page request both on > > book3e and book3s powerpc platforms. After this change > > > > [ 0.000000] Gigantic HugeTLB page not available > > [ 0.473417] HugeTLB registered 16 GB page size, pre-allocated 0 pages > > [ 0.473423] HugeTLB registered 16 MB page size, pre-allocated 16 pages > > > That info is already part of the second line isn't it ? ie > > [ 0.473417] HugeTLB registered 16 GB page size, pre-allocated 0 pages > > pre-allocated 0 pages indicate we didn't allocate anything. So why do we > need to add more details fo kernel output ? Agreed, the '0 pages' message indicates we failed to pre-allocate any pages. The 'pre-allocate' messages are specifically about the kernel command-line requests for hugepages. Not sure I understand the motivation for this? -Nish